The Niles audio switcher will allow you to use the front speakers with the Onkyo and the Nakamichi. It allows you to connect 2 amps to 1 pair of speakers so that you can switch between amps. You hook up the main speaker outputs of both amps to the Niles switcher and then connect the speaker out of the switcher to the pair of speakers that you want to run, which in your case is the large front speakers.